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arXiv · 2312.06489

On local cohomology modules over ramified regular local rings

Rajsekhar Bhattacharyya
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Abstract

In this paper, we show examples of local cohomology modules over ramified regular local ring, having finite set of associated primes. In doing so we consider our ramified regular local ring as Eisenstein extension of an unramified regular local ring sitting inside it. In ramified regular local ring for extended ideal (from the unramified one) set of associative primes of a local cohomology module is always finite. Using the Mayer-Vietoris spectral sequence, we construct examples of local cohomology of non extended ideal, whose set of associated primes is finite. In particular, we choose those non extended ideals whose minimal primes are extended ideals which are all cohomologically complete intersection. These examples of local cohomology modules include the cases whose associative primes also contain prime number $p$.

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Rajsekhar Bhattacharyya. 2023-12-11. On local cohomology modules over ramified regular local rings. https://arxiv.org/abs/2312.06489

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